Pediatrics: Arrhythmias and Bradycardia

Arrhythmias in Children

• Assess arrhythmias for hemodynamic instability or signs of deterioration.
• Signs of instability include respiratory distress, shock, irritability, decreased consciousness, chest pain in older children, and sudden collapse.

Management & Treatment Priorities

• Initial management mirrors that for all critically ill children; support ABC and identify underlying causes.
• Bradycardia is characterized by a slow heart rate for age, often due to tissue hypoxia.

Symptomatic Bradycardia

• Symptomatic bradycardia occurs when heart rates drop below 60/min, associated with cardiopulmonary compromise, leading to hypotension and altered mental status.
• Impending cardiac arrest in infants and children may present as bradycardia combined with hypotension.

Primary & Secondary Causes of Bradycardia

• Primary bradycardia arises from congenital/acquired heart issues, such as pacemaker abnormalities, while secondary bradycardia is due to external factors like hypoxia, acidosis, or drug effects.

ECG Characteristics

• Bradycardia on an ECG shows a slower heart rate, with P waves that may or may not be visible and QRS complexes that can be narrow or wide.

Atrioventricular Blocks

• AV blocks disrupt electrical conduction; first-degree AV block shows prolonged PR intervals, while second-degree can be Mobitz type 1 or 2, varying in the number of conducted P waves.

Treatment Protocols

• For pediatric bradycardia: initially, use bag-mask ventilation with 100% O2; if it persists, administer epinephrine.
• Atropine accelerates heartbeat and enhances conduction and is preferred for bradycardia due to vagal tone or AV block.

Tachyarrhythmias Overview

• Tachyarrhythmias are rapid rhythms from the atria or ventricles, potentially leading to hemodynamic instability with symptoms like hypotension or altered consciousness.
• Narrow complex tachycardia includes sinus tachycardia and is typically triggered by physiological stress, while wide complex tachycardia can indicate ventricular issues.

Management of Tachyarrhythmias

• Begin with obtaining a 12-lead ECG and support airway, oxygenation, and ventilation.
• Synchronized cardioversion is used for atrial fibrillation and stable SVT; sedation is critical before the procedure.

Cardiac Arrest

• Cardiac arrest results from ineffective heart activity, indicated by unresponsiveness and absence of normal breathing or pulse.
• Recognize rhythms associated with cardiac arrest: asystole, PEA, V-Fib, and pulseless V-tach.

Post-Cardiac Arrest Care

• Key steps post-arrest include treating organ dysfunction and ensuring optimal oxygenation, ventilation, and fluid balance.
• Continuous monitoring and advanced life support are necessary to manage any life-threatening conditions present.

Medications and Dosage

• Epinephrine is crucial for symptomatic bradycardia and should be given every 3-5 minutes.
• For adenosine, administer an initial dose of 0.1 mg/kg, with a maximum second dose of 12 mg.

Special Considerations

• Vagal maneuvers can help with SVT, and it is essential not to cover the nose/mouth during ice application for vagal maneuvers.
• Confirmation of ET tube placement should be done using end-tidal CO2 monitoring.

Hemodynamic Compromise Factors

• After resuscitation, understand that decreased cardiac function and inadequate intravascular volume can contribute to hemodynamic issues.